Field of the Invention
The invention relates to a device for measuring friction on a cylinder-piston arrangement, wherein a reciprocating piston is arranged in a cylinder liner of a liner unit, the cylinder liner being decoupled from a cylinder head, and the liner unit is arranged in a liner carrier which is connected to a sensor carrier and which has a rotationally symmetrical receiving region for the cylinder liner, the receiving region being concentric to the cylinder axis, wherein preferably at least one cooling jacket is assigned to the cylinder liner.
The Prior Art
The friction between a piston group which consists of a piston and piston rings and a cylinder liner surface can be determined from the integration of the forces along the piston bearing surface in the direction of the cylinder.
A device for measuring the friction in a cylinder-piston arrangement is known from WO 2012/062725 A1, wherein an inner jacket surface of the cylinder liner is sealed in relation to a cylinder head, in that a sealing element is arranged between the inner jacket surface and a shoulder of the cylinder head which protrudes into the cylinder liner.
A similar device is disclosed in JP 2010-243390 A.
A measuring device for measuring the friction of a piston reciprocating in a cylinder liner is known from JP 60-031037 A. A retaining ring is arranged between the cylinder head and a liner carrier, wherein an annular gap is formed between the retaining ring and the upper end of the cylinder liner, which is filled by a metallic sealing plate.
A device for measuring the piston friction in an internal combustion engine is known from JP 59-088638 A, wherein the cylinder liner is arranged in a cylinder and wherein several O-rings are arranged between the cylinder and the cylinder liner.
In order to enable the testing of different cylinder liners, it is necessary to frequently exchange the cylinder liners in the aforementioned devices for measuring the friction.
Known devices for measuring the friction come with the disadvantage that the liner carrier needs to be separated from the force sensor when exchanging the cylinder liner. This requires a new calibration of the sensor system in each exchange of the cylinder liners. Furthermore, the coolant supply needs to be made leakage-free with much effort in each exchange of the cylinder liner.
It is the object of the invention to avoid these disadvantages and to enable a simple exchange of the cylinder liner.